I'm wondering how true this statement is for the "average" fully patchable analogue synth.
If it is true, then what would you say is the average ratio of inputs to outputs?
I'm imagining a synth which has, for example, 2*VCO, 2*VCF, 2*EG, 2*VCA, 2*LFO, 1*RM, 1*S&H, 1*Noise source.
The reason I'm wondering is that I've worked out a way of easily building a robust and reliable connection matrix, to any size, at a very attractive price, often with parts that many already have in their parts drawers.
The only real issue I can see is that it uses three times the space in one axis compared to the other, so I'd like to get a general idea of whether it should have inputs on the horizontal rows, or on the vertical columns.

I could do a photo set of construction if anyone is interested._________________What makes a space ours, is what we put there, and what we do there.

Well,
Being a connection matrix, the ability to send one output to many inputs is built in, ie just add more pins.
What I really mean is, take away the ordinary idea of "mulitples", and think about the number of inputs & outputs at the PCB. So maybe it would be better to say the number of input and output types. This isn't the whole story, however, as some modules have functionally similar inputs on the PCB. The number of CV ins on a VCO is a good example. So I would be counting those separately. But the square wave out, is counted as one output, regardless of whether it is sent through a "multiple" and on to three VCFs.
Does that make sense?_________________What makes a space ours, is what we put there, and what we do there.

To me, inputs on horizontal rows, outputs on vertical columns seems more intuitive.

If you're looking to even up the square on your matrix, you should build a clock divider/multiplier into your system, 1 input, 16 outputs. You could also do a fixed bandpass bank, 1 input, 8 outputs. How about a sixteen step sequencer with individual outs for each step and some manually controlled quadrature LFOs?

As to WHY there are more inputs than outputs, remember that each module has it's own set of controls for it's output (knobs, switches, etc), and then it's inputs can be thought of as more controls on it's output. More inputs than outputs means that a user has more opportunities to control the outputs of a module. More outputs means that this module would be controlling more modules, and thus a single limited range of controls is influencing a lot of other modules.

Somewhere along the line either designers decided or users demanded that they have more control over individual modules. Then these modules were successful, and they were studied, modified and copied.

if i undertand you correct, you are interested just in the ratio between input and output.

most modules have just one output, correct? (1st type of modules with multiple outputs that come to my mind are multimode filters and sequencers).
the number of inputs depends on the number of voltage controlled features, correct? (we are not interested on multiple input for the same function, or are we?).

Thanks heaps for all the replies!
It pretty well confirms what my gut feeling was, but it's reassuring to get your ideas on the subject. So it's roughly In:Out ~ 3:2, so if the inputs were on the rows, and the outputs on the colums, and the colums take up 3* the row space, that makes 3:6 which is twice as wide as it is high. (roughly)
I realise that the lack of jacks needed on the panel would easily justify the space used by the matrix, no matter how many connections.
I know it might seem like a terrible waste, but I'm actually thinking of re-building my ASM2, (with little additions, like an SNVoice, and chaos generator) in a completely new unit, incorporating a major connection matrix to end up with something akin to a VCS on steroids.
Pre-patched has just too many limitations, and completely patched out with 6.5mm plugs is just to confusing for me. Semi-patched out, as it is now, has some of the advantages of each, but all the disadvantages of both.
Maybe I just think too much about things that don't really matter!
Maybe I'm just trying to distract myself from issues in the real world.
Either way, I thought you might all like to know that even a small, simple and very reliable matrix can be easily built, and I'll show you how if anyone's in need of one. _________________What makes a space ours, is what we put there, and what we do there.

Hmm, well looking at numbers of ins and outs in the stuff I've built, and in the backlog, then *roughly* .....

VCO = slightly more ins than outs
VCF = more ins than outs
VCA = more ins than outs
RM = more ins than outs
MIXER = more ins than outs
ADSR = same-ish, or more ins than outs if a CV ADSR
S+H = same, or more ins than outs
CV Processor = about the same-ish

LFO = more outs than ins
MIDI to CV/gate = many more outs than ins

I like VC inputs on modules - including Resonance, and the LFOs and ADSRs, which skews it towards inputs. Ratio around 3 to 2 I guess...

cheers,
Dave_________________"Everything in moderation, including moderation"

I don't know if it will help you, but I've looked at all of the inputs and outputs on my (semi-)modular flightcase synth (see picture), which I built based mainly on on MFOS circuits, but with a few of my own thrown in. I've used matrices of 3.5mm jack sockets at the back for patching, but there are also a lot of 3.5mm sockets on the main panel for extra patching ability (some of these could have been banana socket really). Anyway, here it goes:

Thanks for that Unc I still have a little bit of tweaking to do on it. When I built the VCOs, I had no tempcos and just used 2K metal film resistors. I've now ordered some, so when I get them I'll put them in and re-tune the oscillators. They're not bad now, but with no temperature compensation, you can't rely on the tuning too much.

Yeah,
I think I'll settle with the In:Out / 3:2 average as a rough guide.
I haven't done anything much lately due to some upheaval in other areas of life. I'll get back on the case ASAP._________________What makes a space ours, is what we put there, and what we do there.

You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot vote in polls in this forumYou cannot attach files in this forumYou can download files in this forum

Please support our site. If you click through and buy from our affiliate partners, we earn a small commission.